ath9k: introduce ath9k_hw_get_scaled_power helper

The computation of the scaled power value in
various eeprom files uses identical code. Move
that code into a helper function and use that
instead of code duplication.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/eeprom.h

@@ -82,6 +82,9 @@
 #define INCREASE_MAXPOW_BY_TWO_CHAIN     6  /* 10*log10(2)*2 */
 #define INCREASE_MAXPOW_BY_THREE_CHAIN   10 /* 10*log10(3)*2 */
 
+#define REDUCE_SCALED_POWER_BY_TWO_CHAIN	6  /* 10*log10(2)*2 */
+#define REDUCE_SCALED_POWER_BY_THREE_CHAIN	10 /* 10*log10(3)*2 */
+
 /*
  * For AR9285 and later chipsets, the following bits are not being programmed
  * in EEPROM and so need to be enabled always.
@@ -686,6 +689,8 @@ void ath9k_hw_get_target_powers(struct ath_hw *ah,
 				u16 numRates, bool isHt40Target);
 u16 ath9k_hw_get_max_edge_power(u16 freq, struct cal_ctl_edges *pRdEdgesPower,
 				bool is2GHz, int num_band_edges);
+u16 ath9k_hw_get_scaled_power(struct ath_hw *ah, u16 power_limit,
+			      u8 antenna_reduction);
 void ath9k_hw_update_regulatory_maxpower(struct ath_hw *ah);
 int ath9k_hw_eeprom_init(struct ath_hw *ah);